The present invention relates to modular concrete forms of the type used to form cavities into which concrete may be poured.
A conventional concrete form is composed of a frame having two pairs of parallel outer steel rails, one pair of rails being perpendicular to the other pair of rails so as to form a rectangular frame. The frame may have a number of parallel inner rails which are connected to the outer-rails to form a number of rectangular bays within the frame. A concrete-forming plate, which may be plywood for example, is secured to the frame.
A number of such conventional concrete forms are typically positioned adjacent each other, and sometimes on top of each other, to form cavities of various shapes and sizes into which wet concrete may be poured. When so positioned, the concrete forms are securely fastened together, such as by bolts or wedges which pass through holes or slots formed in the outer rails of adjacent concrete forms, so that the pressure of the wet concrete does not alter the position of the concrete forms. When the concrete dries, the concrete forms are removed and may be reused.